<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <title>earth</title>
  </head>
  <style>
      html,body{
          margin: 0;
          padding: 0;
          width: 100%;
          height: 100%;
      }
      .main{
          display: block;
          width: 100%;
          height: 100%;
      }
      .btn{
        position: absolute;
        top: 50%;
        left: 50%;
        cursor: pointer;
      }
  </style>
  <body>
    <noscript>
      <strong>We're sorry but smart-city doesn't work properly without JavaScript enabled. Please enable it to continue.</strong>
    </noscript>
    <img src="earth.png" alt="" class="main">
    <button class="btn" type="button" onclick="handleClick()">子页面按钮</button>
    <!-- built files will be auto injected -->
  </body>
</html>
<script>
  function handleClick() {
    alert('子页面事件')
  }
</script>
